Logistics and design issues in the use of biological samples in observational epidemiology

Abstract

Standard epidemiological study designs are well suited to answering questions involving the collection of biological samples. However, different designs are better suited--both for design and logistic reasons--to different questions. The strengths and weaknesses of each design are discussed in relation to markers of exposure, susceptibility and early outcome, and to markers used to classify cancers into biologically defined subsets.